Alpha-Gal Syndrome – Symptoms and Causes

Overview

Alpha-gal syndrome is a food allergy that causes reactions to red meat and other mammal-derived products. This condition typically begins after a bite from the Lone Star tick, which transfers alpha-gal sugar molecules into the human body.

In susceptible individuals, these molecules trigger an immune response, resulting in allergic reactions when consuming beef, pork, lamb, dairy products, or gelatin.

The Lone Star tick primarily inhabits the southeastern United States, which explains why most cases occur in the south, east, and central regions of the country.

However, the geographic range is expanding northward and westward as deer transport these ticks to new areas.

Alpha-gal syndrome isn’t limited to the United States – cases have been reported across Europe, Australia, Asia, South Africa, and throughout South and Central America, often associated with different tick species that carry the same molecules.

Common symptoms include:

• Hives or itchy rash
• Nausea or stomach pain
• Trouble breathing
• Dizziness or fainting
• Swelling of lips, throat, or eyelids

Some people have alpha-gal syndrome without knowing it. Researchers suggest that unexplained severe allergic reactions in patients negative for other food allergies may be linked to this condition.

Prevention tips:

1. Wear long pants and long-sleeved shirts in wooded areas
2. Use effective insect repellent
3. Check your entire body for ticks after outdoor activities
4. Remove ticks properly and promptly

Currently, there is no cure for alpha-gal syndrome. Management involves strict avoidance of mammal-derived products. People with severe reactions should carry epinephrine auto-injectors and seek emergency care when needed.

Signs and Symptoms

Alpha-gal syndrome causes allergic reactions that take longer to appear than usual food allergies. While typical allergic responses to foods like peanuts or shellfish happen within minutes, alpha-gal reactions generally occur 3 to 6 hours after eating certain foods.

Foods that may trigger reactions include:

• Beef, pork, lamb, and other red meats
• Organ meats
• Mammal-derived products (gelatins, dairy)

Common symptoms include:

• Itchy skin, hives, or scaly rashes
• Swelling in the face, lips, tongue, throat, or other body areas
• Breathing difficulties or wheezing
• Digestive problems (stomach pain, diarrhea, nausea, vomiting)

The delayed reaction time often makes it difficult to connect symptoms to meat consumption. For example, someone might not link eating steak at dinner with hives that appear at midnight.

Scientists believe this delay happens because alpha-gal molecules take longer to digest and enter the bloodstream than other allergens.

When to Get Medical Help

Seek medical attention if you experience food allergy symptoms after eating, even if they appear several hours later. Contact your primary doctor or an allergist for proper evaluation.

Don’t dismiss red meat as a possible trigger, especially if you live in or visit areas where alpha-gal syndrome is common.

Get emergency help immediately if you experience serious signs of a severe allergic reaction (anaphylaxis), including:

• Difficulty breathing
• Weak, rapid pulse
• Dizziness or lightheadedness
• Inability to swallow or excessive drooling
• Full-body redness and warmth (flushing)

These severe symptoms can be life-threatening and require immediate medical treatment. Don’t wait to see if symptoms improve on their own.

What Causes Alpha-Gal Syndrome

Alpha-gal syndrome often starts with a tick bite. In the United States, the Lone Star tick is the main cause. Other ticks can also trigger this condition in Europe, Australia, Asia, South Africa, and parts of South and Central America.

These ticks carry alpha-gal molecules from animals they’ve bitten, like cows and sheep. When they bite humans, they introduce these molecules into the person’s body. The human immune system then creates antibodies to fight what it sees as a threat.

For reasons scientists don’t fully understand, some people develop a strong immune reaction to these molecules. This reaction makes it impossible to eat red meat or other foods from mammals without having an allergic response.

People who get multiple tick bites may develop more severe symptoms over time.

Reactions to Cetuximab

Some people with alpha-gal syndrome have allergic reactions to a cancer medication called cetuximab (Erbitux). Studies show these reactions are connected to alpha-gal syndrome.

The antibodies that target alpha-gal molecules in meat also react to the structure of this drug. This happens because:

• The drug contains structures similar to alpha-gal
• The immune system recognizes these structures as threats
• The body responds with an allergic reaction

This connection between the drug reaction and food allergies helped researchers better understand alpha-gal syndrome.

Risk Factors

Living or spending time in the southern, eastern, or central United States increases your chances of developing alpha-gal syndrome. This condition happens more often to people who:

• Spend significant time outdoors in these regions
• Have experienced multiple Lone Star tick bites

The Lone Star tick has expanded its range northward in recent decades. These ticks now appear in large numbers as far north as Maine and as far west as central Texas and Oklahoma.

People in other parts of the world can also develop alpha-gal syndrome. The condition occurs in certain regions of:

• Europe
• Australia
• Asia
• South Africa
• South and Central America

In these international locations, bites from specific types of ticks seem to increase the risk of developing the syndrome. Scientists still don’t understand why some people develop alpha-gal syndrome after tick exposure while others don’t.

Dangerous Reactions

Alpha-gal syndrome can trigger anaphylaxis, a life-threatening allergic reaction that requires immediate medical attention. Without prompt treatment, anaphylaxis can be fatal.

People experiencing anaphylaxis need epinephrine (adrenaline) right away, usually given through an auto-injector like EpiPen or Auvi-Q. After using the auto-injector, emergency room care is essential.

Warning signs of anaphylaxis include:

• Constricted airways
• Throat swelling makes breathing difficult
• Dangerously low blood pressure (shock)
• Rapid heartbeat
• Dizziness or fainting

Medical experts believe some individuals who experience unexplained anaphylaxis episodes may actually have undiagnosed alpha-gal syndrome. These people might suffer repeated severe allergic reactions without understanding the true cause.

People with frequent severe allergic reactions should talk to their healthcare provider about alpha-gal testing, especially if they live in or have visited tick-prone areas.

Preventing Tick Bites and Alpha-Gal Syndrome

Preventing alpha-gal syndrome starts with avoiding tick bites. Ticks that cause this condition often live in wooded areas with tall grass and bushes. Here are effective ways to protect yourself:

Dress Properly

When exploring outdoor areas, wear protective clothing:

• Long-sleeved shirts
• Long pants tucked into socks
• Closed-toe shoes
• Hat and gloves
• Light-colored clothing makes ticks easier to spot

Stick to marked trails when hiking and avoid walking through tall grass or dense vegetation where ticks wait for hosts.

Use Effective Repellents

Applying the right repellents significantly reduces your risk:

Repellent Type	Where to Apply	Notes
DEET (20%+ concentration)	Exposed skin	Avoid eyes, mouth, and wounds
Permethrin	Clothing and gear	Apply a day before use

When applying repellents to children, put it on your hands first, then apply to their skin. Always keep chemicals away from their face and hands.

Make Your Yard Less Tick-Friendly

Several steps can make your property less attractive to ticks:

1. Clear leaf litter and brush regularly
2. Keep grass short
3. Create a barrier of wood chips or gravel between lawns and wooded areas
4. Place woodpiles in sunny spots
5. Remove plants that attract deer, which carry ticks

Check for Ticks Regularly

After spending time outdoors, especially in tick-prone areas:

• Examine your entire body using a mirror for hard-to-see areas
• Check children thoroughly, especially in hair, ears, armpits, and between toes
• Don’t forget to check pets that go outdoors

Act Quickly After Potential Exposure

Taking prompt action after possible tick exposure is crucial:

Shower Immediately

Ticks often remain on skin for hours before attaching. A thorough shower with a washcloth may remove unattached ticks.

Remove Attached Ticks Properly

Use fine-tipped tweezers to grasp the tick as close to the skin as possible. Pull upward with steady pressure.

Don’t twist or jerk the tick, which can cause mouthparts to break off in the skin. After removal, clean the bite area with alcohol or soap and water.

Understand Tick Behavior

Ticks quest by climbing to the tips of grass blades or shrubs with their legs extended, waiting to grab onto passing hosts. Staying in the center of trails helps avoid these questing ticks.